钛合金铣削刀具/工件接触区域温度预测

钛合金（Ti-6Al-4V）因其优良的综合性能广泛应用于航空航天领域中，然而由于其导热系数低、弹性模量低等特性，铣削加工过程中刀具/工件接触区域温度过高，从而导致刀具磨损严重，影响已加工表面质量。因此研究切削过程中刀具/工件接触区域温度具有重要意义。从切削机理出发，将切削区域的3个热源等效为螺旋线热源，其中热流密度计算类比铣削力预测模型中铣削力计算方法，提出包含铣削热系数的热流密度计算模型，并通过实验标定铣削热系数，结果表明热流密度随切削厚度增加接近于线性增加。建立刀具/工件接触区域温度预测模型，通过半人工热电偶测温实验对模型的可行性与准确性进行了验证，实验值与预测值的相对误差在10%之内。提高了刀具/工件接触区域温度的计算精度，并为切削参数的合理选择提供理论基础。

Temperature prediction of tool/workpiece contact zone in titanium milling

Titanium alloy (Ti-6Al-4V) is widely used in the aviation and aerospace industry because of its outstanding overall performance. However, due to its intrinsic characteristics of low thermal conductivity and low elastic modulus, a titanium alloy is difficult to machine, which is featured by the elevated temperature in the machining zone, severe tool wear, and poor surface finish of a machined part. Therefore, it is of a great significance to study the temperature of the tool/workpiece contact area in the milling process. In this study, the three heat sources in the machining zone are assumed spiral-line shaped. A closed-form model, similar to the milling force prediction model, is proposed to calculate the heat flux density and milling heat coefficients. Milling experiments are conducted to calibrate the milling heat coefficients. The results show that the heat flux density is approximately linearly increased with the increase of cutting thickness. A model for predicting the temperature in the machining zone is proposed and validated by experiments using semi-artificial thermocouples. The relative errors of experimental values and predictive values are within 10%. This study offers a guidance to determination of the temperature in the machining zone and optimization of the process parameters in machining processes.